Abstract: This study was designed to validate a new instrument created to measure motives for physical activity (PA) – the PALMS (Physical Activity and Leisure Motivation Scale), which was found to yield sound psychometric properties. Regular exercisers, ages 9 – 89 (M = 28.65; SD = 16.48), from over 30 different fitness and recreational facilities in Israel were invited to participate in this study. A total of 678 completed the PALMS questionnaire consisting of 40 items rated on a 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree). Exploratory factor analysis yielded nine factors that explained 73.29% of the variance: mastery, physical condition, affiliation, psychological condition, appearance, family and friends' expectations, health professionals' and employers' expectations, enjoyment, and competition/ego. We propose the PALMS as a comprehensive and reliable measure of participation motivation in PA.